Data storage tape systems have been used for decades in the computer, audio, and video fields. The data storage tape system includes a tape drive and one or more data storage tape cartridges. In one data storage/drive system, storage tape is driven along a tape path between a first tape reel assembly within the cartridge and a second tape reel assembly within the drive. Regardless of exact form, the data storage tape system continues to be a popular format for recording large volumes of information for subsequent retrieval and use.
With the above in mind, a data storage tape cartridge generally consists of an outer shell or housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub of the tape reel assembly and is driven through a defined path by a driving system. The housing normally includes a separate cover and a separate base. Together, the cover and the base form an opening (or window) at a forward portion of the housing facilitating access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into the tape drive. The interaction between the storage tape and the head can occur within the housing (i.e., a mid-tape load design) or exterior to the housing (i.e., a helical drive design). Where the head/storage tape interaction is exterior to the housing, the data storage tape cartridge normally includes a single tape reel assembly employing a leader block or similar device. Alternately, where the head/storage tape interaction is within the housing, a dual tape reel cartridge configuration is typically employed.
Regardless of the number of tape reel assemblies associated with a particular data storage tape cartridge, the tape reel assembly (also known as a spool) generally includes a hub and one or more reel flanges. In general, the hub includes a core that defines a tape winding surface. The reel flanges are optional, and if employed, are disposed at opposite ends of the hub. To this end, the flanges have a spacing slightly wider than a width of the storage tape to facilitate winding of the storage tape onto, and off of, the tape winding surface.
With this in mind, some form of a brake mechanism is provided to secure the tape reel assembly within the housing during periods of storage. The brake mechanism is generally movable between a locked (i.e., storage) position, and an unlocked position that permits the tape reel assembly to rotate during read/write processing.
For example, the prior art brake mechanisms are normally provided with engagement teeth, or other high friction surface, configured to mate with a corresponding brake surface of the hub of the tape reel assembly. When the data storage tape cartridge is not engaged with the tape drive (i.e., when the cartridge is being handled), the teeth of the brake mechanism are engaged with the brake surface of the hub to prevent rotation of the tape reel assembly. That is to say, the prior art data storage tape cartridges are designed to prevent the rotation of the tape reel assembly when the cartridge is disengaged from the tape drive such that the storage tape, for example, does not inadvertently unravel from the tape reel assembly.
While the above-described brake mechanism addresses unintended unraveling of the storage tape, it can also vibrate and/or wobble within the cartridge housing during read/write processing. In particular, the mass of the brake button during dynamic read/write processing, is known to vibrate substantially in a fundamental frequency. The vibration is accentuated across other frequencies when rotating portions of the tape reel assembly are eccentric, or imbalanced. In addition, any imbalance in the brake mechanism, or contact of the brake mechanism with the rotating tape reel assembly, induces vibrations that result in audible noise during read/write processing.
Data storage tape cartridges have proven highly desirable in the storage and protection of large volumes of retrievable electronic data. Recent advance in data storage tape cartridges have resulted in larger data storage capacities and faster read/write processing. With this in mind, a need exists to reduce deleterious vibrations in data storage tape cartridges that produce noise.